Gumbo is a stew or soup originating in Louisiana, and found across the Gulf Coast of the United States and into the U.S. South. It consists primarily of a strong stock, meat and/or shellfish, a thickener, and the vegetable "holy trinity" of celery, bell peppers, and onion. The soup is traditionally served over rice. A traditional lenten variety called gumbo z'herbes (from the French gumbo aux herbes), essentially a gumbo of smothered greens thickened with roux, also existsThe dish is very common in Louisiana among Creoles, Southeast Texas, southern Mississippi and Alabama, and the Lowcountry around Charleston, South Carolina, and down past Brunswick, Georgia. It is eaten year round, but is usually prepared during the colder months.The stock is always as rich as possible, made with whatever complements the type of gumbo (seafood stock for seafood gumbo, chicken stock for chicken gumbo, etc.).A typical gumbo contains one or more kinds of poultry, shellfish, and smoked pork. Poultry used is typically chicken, duck, or quail. Local shellfish such as the freshwater crawfish and crab and shrimp from the Gulf of Mexico are frequently used. Tasso and andouille provide a smoky flavor to the dish.Gumbos can be broadly divided between the use of okra as a thickener, and recipes using filé powder in that role. Roux may be added to either, and nowadays it is quite common for roux to be the sole thickening agent itself. Mixing okra and filé is uncommon in Louisiana.Another division in types of gumbo is between Creole and Cajun styles. Creole gumbos generally use a lighter (but still medium-brown) roux and may include tomatoes, while Cajun gumbos are made with a darker roux and never contain tomatoes.